v3.22.4
Cover page
Feb. 09, 2023
Entity Information [Line Items]  
Document Type 8-K
Document Period End Date Feb. 09, 2023
Entity Registrant Name MDU Resources Group Inc
Entity Incorporation, State or Country Code DE
Entity File Number 1-03480
Entity Tax Identification Number 30-1133956
Entity Address, Address Line One 1200 West Century Avenue
Entity Address, Address Line Two P.O. Box 5650
Entity Address, City or Town Bismarck
Entity Address, State or Province ND
Entity Address, Postal Zip Code 58506-5650
City Area Code 701
Local Phone Number 530-1000
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Common Stock, par value $1.00 per share
Trading Symbol MDU
Security Exchange Name NYSE
Entity Emerging Growth Company false
Entity Central Index Key 0000067716
Amendment Flag false